Boy saved by marrow swap will give life to his brother

And the 13-year-old schoolboy is about to show his gratitude in the best way possible - by becoming a donor himself.

The recipient will be his six-year old brother, Luke.

Both boys, along with brothers Joshua, 14, and Daniel, ten, were diagnosed with X-linked lymphoproliferative syndrome, a rare genetic defect, in November 2003.

Doctors told their parents the boys were unlikely to live into their teens unless they had bone marrow transplants.

The three eldest boys have all since had successful transplant operations.

And Nathan's recovery is so marked that he will now be able to donate stem cells for Luke's transplant in March.

Doctors at Great Ormond Street Hospital in London told the family the donor they had hoped to use for Luke was no longer available.

Luckily, big brother Nathan is a perfect match - and fit and healthy.

'Nathan is delighted that he will have the chance to save the life of his brother,' said his father, David, 43, at the family home in Romsey, Hampshire.

The boys' mother, Allison 39, donated peripheral blood stem cells for Joshua in June 2004. Nathan and Daniel found their donors after thousands responded to a massive campaign by the Anthony Nolan Trust.

As a veteran donor herself, Mrs Hartley has been explaining the procedure to Nathan, who had his transplant in November 2005.

As a donor, Nathan will be injected with drugs to increase the amount of stem cells released into his bloodstream over four or five days.

Blood will then be removed through a needle placed in one arm. The blood will then pass through a machine that separates the blood stem cells.

The remaining blood, minus the stem cells, will be returned to his body through a sterile needle placed in the other arm.

The procedure can take up to two days depending on the amount of stem cells required.

Luke will have chemotherapy to destroy his bone marrow and make room for the new marrow transplant. His brother's stem cells will be transferred to Luke intravenously, in a process similar to a blood transfusion.

The stem cells will then find their way to the bone and start to grow and produce more cells.

'Nathan has made a brilliant recovery and is doing very well - you wouldn't think anything was wrong with him,' said Mrs Hartley. 'Luke has been fantastic. It is incredible.

'He has seen the other boys go through various things and he hasn't been fazed by it.

'He can't wait. He just thinks it's his turn. That's a lot of the battle really, coping with a child who is not really understanding what's going on.

It's just become part of their everyday life. We just keep really positive about it.'

X-linked lymphoproliferative syndrome is an extremely rare condition which affects only males - females can have the condition, but not be affected by it.

It is a genetic defect that causes the immune system to respond abnormally to some viral infections.